The present invention relates to a flat panel display device which includes electron beam sources having cathodes which emit electrons in response to an electric field and a phosphor screen which is excited by the electrons emitted from the electron beam sources; and, more particularly, the invention relates to a flat panel display device which uses a carbon-based material, such as carbon nanotubes, micro carbon fibers, diamond or the like, as cathodes which emit electrons with a low electric field.
Recently, as represented by diamond, carbon nanotubes or the like, electron emission materials have been found which can produce an emission of sufficient electrons with an extremely low electric field as compared to field-emission-type electron sources which use a conventional metal material as a main material. A flat panel display device which uses such an electron emission material as a material of the cathodes is described in patent literature 1 (Japanese Unexamined Patent Publication Hei11(1999)-265653), for example.
The flat panel display device described in this patent literature 1 is comprised of a first panel, which has a plurality of electron sources constituted of cathode lines made of a stripe carbon film disposed on a first substrate, and a second panel, which has phosphors arranged to face the above-mentioned carbon film cathode lines in a direction perpendicular to the carbon film cathode lines (or a crossing direction, this expression being used hereinafter) in a stripe pattern, and anode lines are provided on the second panel, which is laminated to the first panel. Further, by selecting portions of the cathode lines and the anode lines, electrons are emitted from the cathode lines at crossing points of these lines, thus making the above-mentioned corresponding phosphors emit light, whereby an image is displayed.
Further, another device which is different from the above-mentioned device is described in patent literature 2 (Japanese Unexamined Patent Publication Hei10(1998)-149760). In this patent literature 2, a flat panel display device is described which is comprised of a first panel, which forms stripe-like pull-out electrodes at positions close to stripe-like emitters (also referred to as cathodes), which are formed of an electron emission material having carbon nanotubes formed on a first substrate, wherein the pull-out electrodes are arranged in a direction perpendicular to the cathodes, and a second panel, which has phosphors on planer anodes which are formed on a second substrate laminated to the first panel.
By selecting respective portions of the pull-out electrodes and the cathodes and applying a voltage to these portions, electrons are emitted due to an electric field applied between the selected pull-out electrodes and the cathodes, thus making the phosphors formed on the planer anodes emit light so as to display an image.
Further, a basic structure of electrodes in which the distance from the cathode surfaces and the distance from the control electrode surfaces to the anodes are set to be substantially equal is described in patent literature 3 (Japanese Unexamined Patent Publication 2002-25478).
As mentioned above, with the use of carbon nanotubes as the electron emitting material, it is possible to generate electron beams with a relatively low electric field, and, hence, a flat panel display device can be readily obtained.